package com.biostime.dingdingbox.modules.db.service;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

public class HttpRequestService {
	 /**
     * 向指定URL发送GET方法的请求
     * 
     * @param url
     *            发送请求的URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return URL 所代表远程资源的响应结果
     */
    public static byte[] sendGet(String url, String param) {
    	
        byte[] data = null;
        try {
        	
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            
            // 建立实际的连接
            connection.connect();
            
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            
            //获取输入流的字节数组
            data =toByteArray(connection.getInputStream());
            connection.getInputStream().close();
            
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        
        return data;
    }
    
    public static byte[] toByteArray(InputStream in) throws IOException {
        ByteArrayOutputStream out=new ByteArrayOutputStream();
        byte[] buffer=new byte[1024*4];
        int n=0;
        while ( (n=in.read(buffer)) !=-1) {
            out.write(buffer,0,n);
        }
        return out.toByteArray();
    }

    /**
     * 向指定 URL 发送POST方法的请求
     * 
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            conn.setRequestProperty("Accept-Charset", "utf-8");
            conn.setRequestProperty("contentType", "utf-8");
            
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(new OutputStreamWriter(conn.getOutputStream(),"utf-8"));
            
            // 发送请求参数
            out.print(param);
            
            // flush输出流的缓冲
            out.flush();
            
            // 定义BufferedReader输入流来读取URL的响应            
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }    
    
    /** 
     * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址, 
     * 
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？ 
     * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。 
     * 
     * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 
     * 192.168.1.100 
     * 
     * 用户真实IP为： 192.168.1.110 
     * 
     * @param request 
     * @return 
     */
    public static String getIpAddress(HttpServletRequest request) { 
      String ip = request.getHeader("x-forwarded-for"); 
      if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
        ip = request.getHeader("Proxy-Client-IP"); 
      } 
      if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
        ip = request.getHeader("WL-Proxy-Client-IP"); 
      } 
      if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
        ip = request.getHeader("HTTP_CLIENT_IP"); 
      } 
      if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
        ip = request.getHeader("HTTP_X_FORWARDED_FOR"); 
      } 
      if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
        ip = request.getRemoteAddr(); 
      } 
      return ip; 
    }     
}
